Dam forming device



Feb. 3, 1942.

w. H. SILVER DAM FORMING DEVICE Filed April 1, 1940 2 Sheets-Sheet 1 E W vL m mH V mm T 8 2 x M 3 5/ 6 3 34. .U 0 4 5 6% W b W k 5 3 4 23M p w w a u w. 1 om 8 .a a M m 6 Z w 5, mm} 6 7 7 1;: LL/ 3 02 r 1 M 06/l0 fi I; /J w, w 7 w \W\ V M 6 W 3 w 3 5 5 2 24 6 4 3 .3

1942- w. H. SILVER DAMF QRMING DEVICE 2 Sheets-Sheet 2 Filed April 1, 1940 a l N VEN TOR:

ALTER H SI V R I T e present invention .fied fo'rming of connecting Patented Feb. 3, 1942 1 1 Company, Moun 11]., a corporation of Illinois Aliiplication Ailril. 1, 19 0,- seriai 1%; time 14v claims.

filed Decernber 8, 19367 dated April2, 1940-...'.,

nevi B et N 96-5 3 relates to dam forming attachments ion use {with listersfand other furrow forming implements or the like, andwmore particularly to; implements for forming spaced apart dams associated with planting and like implements.

. The principal object,offthe"present 'invention is to provide. a damming device for attachment to a lister'. Another 7 object of this, invention-is theprovision of a dammingjdevice"particularly adapted. v to operate behindlthe, planting units 7 of a lister or the like Another feature-of. the present invention is the provision of a damming attachment having.xblades which, are shaped to accommodate the furrow when; they operate.- An additional feature of this invention is to pro videv a damming attachmenthaving blade'sfpfar ticularly constructed so as to operate behind he presswheels-oi the lister; with which the d mining attachment isassociatedtl r further. feature of thisinven disposed soga s toavoiddisturbing the seedplanted. Another feature oflthis invention. resides in the: provision of meansfor adjusting the damming'device so as to correspond to the position of the. furrow opening tools. I These and other" objects anda tien: ot a preferred embodimentp Reference is had to the appended drawings'in which I liigure 1 is a plan view of; a two-row lister attached dam forming device embodying the principles of the present invention; g t

Figure 2: is a partialsectional viewtaken along the line 2-2 of Figure 1;showingtheimp1emehts in ground'gengaging positionjQ M Figure 3 is a view similar to the damming device..-

"Referring now to the dra ings, thefliste'r, n;

I 7 some thepm vision-oi a damming attachment havingblades l Wantages present invention will hecome apparentafter a consideration of the iollowin'g detailed descripvlongittidim .-s he fo w rd ends o are bent downward y, as t 9,. andj ri idly interconnected bi means of a, transverse member 1.0, -A;- secondrtljansverse, member .I l, disposed to thenreanof; member I0, is likewise fixed at. its ends TtoQthe-beams;1,8, providing for a rigid structurato which thevarious tools and support,-

i i lwhelsmay eattached.

'In the pr'e e ede bodime t. shown and escribed herein, the .lister ifis, intended for, use Withatractor -(notrshown) towhich the Irame BfiS CDnnBQtGd. by means of a supplementa or d'raftlframe [2, The draft. frame, 12 consists of two bail members l3 having links IA fixed to the rear ends thereof. by bolts i5. 'lhe links M are pivotally connectedtby pivot bolts Hi to the ends or the'bea-msfl, 8, for v'ertical swinging, move- :ment; :The bail members 13 converge forwardly tund a-rejoined to form asing'le draittongue I]. A clevis i8 atrthe, forward. end or the .drait tongue l'Lprdvides nls foi; flexiblyconnecting the draitjframe [21 othedrawbar l.9 oithe tractor.

1 I Iiiiedto theY-rearend of each oi the. beams fixed the te s yldin ool bar lby m a s c a ps 22. are two. late 11,; a and; extending rrear'wardly therefrom: is a bracketmemberill; ,Altransversetool-bar 2| of Jmiformss' uare crosstsection is supported in the ends-oi the two bracket members. 21!. and rigidly C am d to the 'erally spacedi'planters .23, each comprising a downwardly; an r'earwardly curved tool shank 5 at the'lower endof which is carried .aiurrow opener 2fi,; 'A' .bracket,- indicated. at. 31L which -,a seecLeontainer -MJ seed selecting and dropping mechanism 3,2, and seed spent 33. The spout 33 immediately, covered with soil by the coveri-ngv M) v Figure. 2 showing the implements raised in transport position and Figure 4is a fragmentary view, showing amodimeansassociated with drops the-scedjinto the bottom of the furrow directlybehind; the furrow opener 26. where it is :shovels.:34= and: pressed- -down. byipresser wheel means, preferablyin'theform of'a pair of trailing -pre ss;wheelsfliiS.-i;The latter are of more. or

filess conventional, construction, each having rim 1 or; flange and-iboth-wheels of" each-unit being mounted-rat an flangle' so that the soil-is com- Ipacted; mut the deposited' seed,z with the soil "higher directly abovetheg seed than at the side ,Whera the flanges orrims of the wheels run, in

convex; term,- as' is usual in planting, implements. The two press wheels 35 shown as associated with eachJ-mit, compacts the soilinvsubstantially the same manner-and serve. as a. single wheel with dicated, in its entirety by the reference numeralrims orflanges :spaced apart the. same. distance ,diStanQebet een the lower portions of the wheels 35, both forms of press wheels being old and well known.

The covering shovels 34 and press wheels 35 are carried on a frame 36 comprising a pair of spaced longitudinal members 48 which are bolted at M to the tool shank 25 and are braced by struts 42. The rear end of the frame 36 includes a vertical sleeve 43 in which is journaled a spindle '44. The lower portion of the spindle 44 is bent rearwardly, as at 45, terminating in an axle housing 46, and the axles 58, upon which the furrow wheels 35 are journaled, are carried in the housing 46,

The forward portion of the lister is supported on a pair of laterally spaced ground wheels 5|, 52 which are fixed on live axles 53, 54, respectively. The lister frame 6 is connected to the axles 53, 54 by means of a bail 55 which is journaled for vertical swinging movement in .two bracket members 56; the latter being fixed,

as by welding, to the tool bar 2I and extending forwardly therefrom. The live axles53 54 are journaled in the ends of the bail 55.

.Power for driving the seed selecting and dropping mechanisms 32 of the planters 23 is derived from the right ground wheel 52 and is transmitted by a sprocket and chain drive, indicated by the reference numeral 68, from the live axle 54to an intermediate sprocket element, indicated at 6 I, which is journaled on the transverse portion of the bail 55. vA second sprocket and chain drive, indicated by the reference numeral 62, transmits the power back to a seeding mechanism drive shaft 63. v v

Lifting of the lister 5 is accomplished byv means of a self-interrupting clutch mechanism 64 of conventional design well known in the art, and adjustable connecting linkage which will be described shortly. As the details of the clutch have no bearing on the present invention, it is deemed sufficient to state that in general it comprises a continuously rotating driving element 65 which is operatively connected with the live axle 53, a normally non-rotating driven member 66 which is journaled on the axle 53,'and means for optionally engaging and automatically disengaging the driving element and driven member after a half revolution. Engagement of the two members iseffected by pulling on a trip lever 61 which is pivotally connected to the adjacentarm of the bail 55 and operatively connected with the engaging mechanism disposed within the clutch 64. The driven clutch member 66 includes an inwardly directed sleeve portion 68 which embraces the axle 53, and the inner end of which is provided with a crankarm 18. Connected at one end to the crankarm I8 bymeans of a pivot bolt 'II is a link 12, the other end of which is connected by a pivot bolt I3 to a hand lever I4. The hand lever 14 is swingably connected to the frame member .I by means of a pivot bolt I5 and is held in position by a latch I6 which engages a notched sector 88. A grip lever 8| at the handle end of the hand lever I4 controls the latch 16. The hand lever I4 raises and lowers the front of the frame 6, and hence determines the operating depth of the blades or scrapers, of the its entirety by the reference numeral 82, com- (I prising two scraper blade assemblies 83 fixed on opposite ends of a transverse shaft 84, is disposed to the rear of the lister 5 with each of the blade assemblies 83 aligned with its respective planter 23 to operate in the furrow formed thereby. Each blade assembly 83 consists of three blades or scrapers arranged radially about the shaft 84 at degrees spacing. The sides of the blades 85 are tapered to accommodate the sides of the furrow, while the center portion of the outer edge is relieved, as at 86, to clear the seed planted by the planter 23 and prevent its being disturbed, the remaining portions of the outer edge of each blade 85 being formed so as to lie, in operative position, on substantially the level of the press wheel means, as best shown in Figure 2. As best shown in Figure 1, the width of the scrapers or blades 85 at their outer edges is approximately the same as the distance between adjacent press wheels 35,

both conforming generally to thefurrows opened by the bottoms 26. Adjustable gauging runners 98 are fixed to the back sides of the blades 85 to hold the latter at a constant predetermined working depth. From Figure 2 it will be seen that the lower edge of the blade 85 in operating position is at substantially the level of the press wheels 35. Bracket members 9| connect the blades 85 to a pair of spaced plates 92 which are fixed to the shaft 84.

Connecting the dam forming device 82 to the lister 5 is a frame including a forwardly extending draft beam 93, at the rear portion of which are fixed two rearwardly diverging members 94 braced by a cross member'95. The shaft 84 is journaled in the ends of the members 94. The forward end of the draft beam 93v is pivotally connected by means of a transverse pivot bolt 96 to a link I88, providing for vertical swinging movement of the beam 93. The link I88 is secured by a bolt I8I to a bracket member I82 which is clamped to the tool bar 2I.

In the operation of the dam forming device 82,

the scraper blade assembly 83 is held against opened up by the furrow opener 26. The operatively positioned blade 85 engagesthe sides of the furrow and scrapes soil from the sides thereof until sufficient has been accumulated to form a dam. At this point the blade assembly 83 is released and permitted to rotate, depositing the accumulation ofsoil across the furrow, while the succeeding blade 85 is swung downwardly and locked into operating position. Thus, each blade when in engagement with the bottom of the furrow serves to rotate the whole blade unit when the latter is released; in other words, each blade serves as ground engaging means for advancing the others. In the embodiment shown and described herein, the dams are spaced an equal distance apart by escapement mechanism actuated by the ground wheel 52 and thereby controlled by the forward movement of the implement over the ground. It has previously been explained that the seeding mechanism shaft 63 is operatively connected to the live axle 54 by means of sprocket and chain drives 68 and 62 and therefore rotates at a speed directly proportional to the speed of rotation of the ground wheel 52. The shaft 63is employed to actuate the escapement mechanism for the scraper blade assemblies 83, therefore, and driving connection is made through a train of speed reduction gears I83, I84, I85, and I86 to rotate a cam I81 which tension against the disk I23.

v is journaled' on the shaft 63. .;:Gear I ou t. fixed on the. shaft-. 63; bothsgears-kl 34,; I05 are: fixed: on

a,countershaftktto whic-h'Tis-yjournaledf ina a bracket III and-thezdriyen ear" l llfiis journaled on the shaft 63" and' fixedlyqconnected; to

.thecam IIJ'I. The bracket llljisgiournaledion the shaft 63-for suppcrtand: also connected. to the link I by'means of thepivot bolt 96, the latter connectionz holding the bracket II I; against rotationaboutitheshaft'63. Acam followerI08 attached, to oneyend-of a rearwardly extending rod II2, engages thecam I01 and with each revolutionof the-latterfiis' drawn forwardly and then released to drop back to: its originalposition;

The rear end of themed II2 i's swingably connected. to ailink I I3 which'is pivotally connected at. I I 4 tothe draft beam.93.'- A second rod H5- bolt/96; A. transverse rock; :shaft I42; ;is joure.

naled; in c the ends. ofg'the' bracing; members; [40, 1:41;, which extend a short distance rearwardly fof the bracketsi lt34',rand fixedto the. rock shaft 142 adjacent the members. 140, I14 I are two'reariwardly. extending lifting: arms, I4 3, I44: Also fixed to the shaft 1'42; midway betweenthelift- I .ing arms I43, I44 is anupwardlyextendingcrank arm I45-',the purpose 'of which'shall' be explained later.

- Fastenedto thelouter end of: each of lthe lifting arms I43, I44? byla bolt I46 is a chain [41 which is connected-at its :lower end to a transversebar I50..- The latter is fixed to tw'obrackets is likewise swingably-connectedto the link H3 I and extends rearwardly to' a-"pivotal' connection at 'IIB with a rearwardly inclined detent. arm H1. The latter is swingably' connected at.I

"I'5-I which are bolted by'bolts.:l52 to the draft beam .93. :.Thus, rocking thelifting arms I43,

to a stub I2I which projects upwardlylfrom the,

end of the draft beam 93. Thus, it will be seen I that thereciprocating movement. of the rod' I'I2 as'the attached cam follower is acted upon by the cam Ill'I is transmitted back to the detent arm I I! to swing the latter in a vertical plane.

- behindthe'press wheelszand the listerbottoms 26, I

I44 raises or lowers the "draft: beam =33 and at-.v

tached dam forming devic'e82. v V v. In the preferred embodiment shown Ianddescribedlh'erein; when the implement'is inoperae,

tion, theblades or' scrapers 85, normally. locked against lrotatiomlare drawn along the furrows the: dammingbl'ades being normally heldito T their I A roller I22 journaled in the outer end ofthe detent arm I I1 bears against the periphery ofa circular disk I23 whichv is fixedon the shaft ,84. The disk I23 is notchedat three 120- degrees spaced points I24, and-when the blade assembly 83 is in operative position, one of the notches I24 is engaged byxthe-roller I22 thus holding the disk I23,.sh'aft.84; and scraper'blade assemblies 83 against rotation. When the detent arm II! is swung upwardly under'the influenceof the cam I01, the roller In is disengaged from the notch I24 and theiscraper blade assemblies 83 are permitted'to rotate. A spring I25 con work" by. their own weight; andlimitedvin their downward movement bythe chain's" I41 as when 'the' soil ,is light or soft. The blades serve' to'level the surface at the bottom-of thefurrow an'd l'ocse soil collects" in front of v.the'blades until'they are trippedibyethe latch mechanism I26,'which then nected at one end by means of a link I26 to the detent arm 1, and at the other end by a link I 30to a stub I3l extending downwardly from'the end of the draft beam 93; holds" the roller under Itvhas'previously been pointed out that the I lister 5 is raised to inoperative or transport post-'- tion' by action of L the self-interrupting clutch mechanism 64 on linkage connected to the'frame 6, which causes the bai1 55 to be swung downwarclly and thereby raises the front endfof the .is transmitted'by ai connecting rod I I54?"to "the leavesw dams acrossthe' furrow. The "rock shaft 142. :is rocked by linkage connecting mama frame" I 2 with 'the'crank arm I451 Whenthe lister 5 israisedJto inoperative'or transport position (Figure '3') by actuating the clutch 64 and tilting the fraineG, thefront ends of the beams -I, 8' are raised relative to the point of connection ofthe draft frame I2 tothe tractor drawbar I9,

"causing the draft frame I2to swing relatively downwardly about the pivot bolt "It..w'l'loe result ing' angulation between the" lister frame 6 and draft frame I2 is. translated into? reciprocating,

motion byinieans ofabrankstructure, indicated inits entirety by thereference'numeral I53, and

lister 5 sufficiently highfor the planter tools to clear the ground Swinging thehand lever 114 to effect a depth adjustment also raises and lowers the lister frame a certain amount by tilting the same about the press wheels 35. Obviously, I

this tilting of the frame longitudinally about the rear furrow'wheels 35 will not, in'itself, raise the dam formingdevice 82 "Which'isdisposed' to the rearof the furrowwheels.)ThereforeQsup plementary; lifting linkage is required for lifting the dam forming deviceat: the same time'that' the listeris raised; and to this end a transverse beam I32 has been provided, upon which is carried lifting mechanism" now to be described.

The beam 132 is bowed"upwardly in the center crank structure I53 comprises a pair of I members 155 Whichf are' connected by *the" bolts H5 to the draftframe" I 2 adjacent the. links I 4, and. extend upwardly 'in' converging relation to joinv onop,- posite sides .ofg'a bracing strut I56. rThethree member'sare-joined by abolti- I50 at this point and the-two members I55 'continne-upwardly'in I parallel relation and spaced apart the-thickness portion thereof to provide clearance for the draft beam 93. as the latter is swung,upwardly,- and to the ends ofthe transverse beam I32 are v bolted angle brackets I33 which are fixed to the tops of the verticalsleeves 43; A pair of brackets I34 is spacedsymmetrically on either sideof the cured to the brackets I34 by bo1ts-I36 andsextending diagonally fonwardlw and downwardly center of thebeam I32'and. fixed thereto. .1Se-

of the intervening bra'cinglstrut' I569? The strut I56:;extends.ldo-wnwardly and" forw'ardlyfand is fixed at I'5'Ito the 'draft'tongue I I; providing for longitudinalrigidity of thel'crank structure I53.

The connecting rod I154 is carried betwen the ends; of'fthe mem-be'i s"l:55 and is pivotallyycom nected. thereto by a pinib-olt-ifi I.-

.Additional perforations I'62,in the :end of the"connecting"frod v i I 54 I "provide means for adjusting th'ef working j deptht'of the darn forming devic'etz by changing the angular. position ofv the crank' arm 1' I45 relatil/8.110 the cranki'structure I53; Thecormecting rod I54 is pivotally' connected at itsrear end to the crank arm yl 45 by meansaofla pivotbolt I 63.

While the principal function'iof this linkagezisto raise the damming units 83f toiithei-r upper .or

transport ipositionu wheneyer the halt-revolution clutch-64 is actuated {to raiserthe lister bcttenls 26 out of the ground and intotheir inoperative or transport position, it will nevertheless benoted that operating the depth adjusting lever 14 will also'cause the hitch frame I2 to swing through a limited extent, and that this swinging movement also acts through the linkage I54 and associated parts to rock the lifting arms I43, I44, and hence adjust the operating position of the damming blades in so far as varying theposition of the lifting arms I43. and I44 will change the lower limits to which'the damming attachment is permitted to move by virtue of their chain connection I41 with the arms I43, I44.

By this linkage arrangement, the weight of the dam forming device 83 is made to bear downwardly upon the ground wheels 5|, 52 when the implement is raised, increasing thetraction and thereby improving the operation of the power lift clutch 64 which derives its power from the tractive force of wheel 5|.

Under some operating conditions the weight alone of the dam forming device is not sufficient to insure that the damming blades will always operate in the bottom of the furrows, and to take care of such situations I have devised certain modified connections between the dam forming device and the front draft frame, the angular position of which relative to the lister frame controls the position of the dam forming device. Such modified connections will now be described.

Referring to Figure 4, it will beseen that the draft frame I2 is pivoted to the lister frame 6 at the down-turned ends of the beams I and 8 in the same manner as described above; However, the upwardly extending members I55, instead of carrying a pivot bolt I6I as in Figure 2, pivotally receives a sleeve I10 by means of trunnions I1I. A connecting rod structure I54a, quite similar to the connecting rod structure I54 described above, is provided at its forward end with a threaded portion I12 and the front end of the connecting rod I54a is slidable in the sleeve I10. A spring I15 encircles the forward end of the rod I54a in front of the sleeve I10 and an adjusting nut member I19 having a crank I80 is screwed onto the threaded end I12 of the connecting rod I54a. Rearwardly of the sleeve I10 is a second and somewhat stronger spring I82, the front end of, which bears against the sleeve I10 and the rear end of which bears against a collar I83 which is adapted to be fixed to the rod I54a in any suitable manner, such as a set screw I84 by which the position of the collar I83 may be adjusted. At its rear end, the rod I540. is connected by the bolt I63 to the upper end of the arm I45, in the same manner as described above in connection with the connecting rod I54.

The lower end of the arm I45 is fixed to the rock shaft I42 in substantially the same manner as described above, and likewise the rock shaft I42 is supported in the ends of the bracing members I40 and MI as shown in Figure 1. A pair of arms I43 extend rearwardly in laterally spaced relation from the rock shaft I42, and each is formed to receive a sleeve I90 having trunnions I9I by which the sleeve is pivoted to the rear end of the associated lifting arm I43. A rod' I92, having its upper end threaded, is slidably disposed in each sleeve I90 and extends downwardly and is pivoted, as at I94, to the outer end of the transverse bar I50 at substantially the same point where the chain I41 is fastened. As in the form of the invention shown in Figures 1, 2 and 3, there are two rods I92, spaced apart laterally as are the chains I41. A spring I95 bears at its upper end against the sleeve I and at its lower 'end against an adjusting collar I96,'there being a spring I encircling each of the pressure rods I92. The lower end of each pressure rod I92 is held in place in the transverse bar I50 in any suitable manner.

By virtue of the pressure springs I82 and I95, and. the associated adjustable collars I83 and I96, any degree of pressure desired may be applied against the dam forming device for holding the blades down to their work, the springs reacting against the swingable draft frame I2. As described above, the depth adjusting lever 14 may be swung to raise or lower the lister bottoms 26 to adjust the depth of operation thereof, and since this movement of the hand lever 14 results in generally vertical movement of the main frame 6 relative to the draft frame I2, it will be seen that movement of the depth adjusting lever results in'varying the pressure which the springs I82 and I95 exert, since they react against the draft frame I2, as just stated. When the parts are arranged as shown in Figure 4, movement of the depth adjusting lever 14 to the position of deeper plowing, results in applying slightly increased pressure against the damming blades, and since the furrows are deeper, this additional pressure ensures that the blades will be held to the proper position. Thus, in its generic aspect, the connections shown in Figure 4 are so arranged that movement of the depth'adjusting lever 14 also occasions certain adjustments for the damming device at the rear of the lister. The construction of Figure 4 has the advantage, as compared with the construction shown in Figures 1 and 2, that the control of the damming units is more positive, yet by virtue of the cushioning action of the springs, the damming units may accommodate irregularities in the ground surface.

While I have shown and-described above the preferred means in which the principles of the present invention have been incorporated, it'is to be understood that my invention is not to be limited to the particular means shown and described above, but that, in fact, widely diiferent means may be employed in the broader aspects of my invention, as defined in, the appended claims.

What I claim, therefore, and desire to secure by Letters Patent is:

1. A damming attachment for a soil tilling implement having a wheel supported frame carrying a furrow opener and a pivoted hitch member, said attachment including means serving as a frame connected with the'implement frame, a scraper blade assembly rotatably' mounted on said attachment frame means and includin a plurality of scraper blades, mechanism including a member 'pivotallymounted on said attachment frame means for releasably holding one of said scraper blades at a time in operative position, and means connected with the hitch member and with said attachment frame for applying yielding pressure to said scraper blade assemblies to hold them down'in ground engaging position.

2. A damming attachment for a soil tilling implement having a frame carrying a pair of laterally spaced furrow openers, means for raising and lowering said frame, planting means for depositing seed in the furrows formed by said furrow openers, and press wheels in rear of said planting means, said attachment includin means serving as a frame connected with theimplement frame, a pair of scraper blade assemblies movably connected with said implement frame rearwardly of said press wheel means and each including a plurality of scraper blades, means pivotally mounted on said implement frame .for

swinging movement relative thereto, and resilientconnections between said last mentioned means and said scraper blade assemblies for yieldingly holding the latter in operative ground engaging position. I

3. In a tillage implement, a furrow opener, means in rear thereof for depositing seed in the furrow formed by said furrow opener, press wheel means in the rear of said seed depositing means for pressing soil about said feed, a dam forming device rearwardly of saidpress wheel means and adapted to be operated to form dams in the furvice, and means for resiliently holding said dam forming device in operating position.

4. In a tillage implement, the combination of a lister having a lister frame, a pair of lister bottoms connected therewith in laterally spaced relation, and a pair of planting units for depositing seed in the furrows opened by said lister bottoms, a damming attachment including means serving as an attachment frame, and a pair of rotatable damming blade assemblies movably con-,

nected withsaid attachment frame means'and disposed behind said planting units, each assembly including blades shaped to engage soil in saidfurrows and to clear the speed deposited therein, and means for applying pressure to said blade assemblies for h01dll1g them in their operating position.

5. An implement comprising a main frame, ground engaging tool means fixedly'connected with said main frame, a draft member connected together for relative swinging movement, a second ground engagin tool means connected withsaidmainframefor movement relative thereand means acting against said attachment frame between the blade assemblies for applying pressure to said attachment frame for holding said blade assemblies in theiroperating position.

8. In a tillage implement, the combination of a lister having a lister frame, a pair of lister bottoms connected therewith in laterally spaced relation, a hitch frame swingably connected with saidlister frame, and a pair of planting units frow, means for operating said dam formin de-z.

for depositing seed in the furrows opened by said "lister bottoms, a damming attachment including means serving as an attachment frame, and a pair of rotatable damming blade assemblies mov ably connected with said attachment frame means and disposed behindsaid planting units, each assembly including'blades shaped to engage soil in said furrows and to clear the-seed deposited therein, andmeans responsive to movement of said hitch frame relative to said listerframe for applying pressure to said blade assemblies for holding them in their operating position.

9. In an agricultural machine, two relatively I movable ground working tool means, means for applying draft to one of said tool means, and means reacting against said draft applying means for holding the other tool means in operative position.

10. In an agricultural implement, a frame, a

lister bottom carried thereby, a hitch frame piv otally. connected therewith, a ground engaging tool movably connected with said frame, and

' means connected with said hitch frame for holding said tool in operative position.

11. In an agricultural implement, a frame, a lister bottom carried thereby, a hitch'frame pivotally connected therewith for transmitting draft thereto, a ground engaging tool movably connected with said frame and offering less ground to in a generally vertical direction, said fixedly mounted tool means offerin greater resistance to movement through the soil than said movable tool means, and means controlled by the position of said draft member relative to said main frame and reacting against the latter and operative, at least in part, by virtue of the greater resistance of said first tool means for applying yieldingpressure against said second tool means. 7 r

6. An implement comprising a main frame an a draft member connected together for relative swinging movement, a tool holding structure (3011- i furrow openers, press wheel means in the rear of said seed depositing means for pressing soil about said seed, a dam-forming device rearnected with said main frame for movement 'relative thereto in a generally vertical direction, means controlled by the position of said draft member relative to said mainframe for applying v yielding pressure against said tool holdin structure, and means for swingin the draft member relative to said main frame for varyin the pressure applied to said tool holding structure.

7. In a tillage implement, the combination of a lister having 'a'lister frame, a pair of lister bottoms connected therewith in laterally spaced relation, and a pair of planting units for depositing seed in the furrows opened by said lister botwardly of each'of said press wheel means for forming dams in the furrows, means for operating said dam forming devices, means for resiliently holding said dam forming devices in operating position, and means including a pair of laterally spaced arms pivotallymountedon the rear of the implement for raising said dam forming devices to inoperative position. I

14. Ina tillage implement, the combination of a lister having a lister'frame and a pair of lister bottoms connected therewith in laterally spaced toms, a damming attachment including means serving asan attachment frame, and a'pair of ro-.

tatable damming blade assemblies movably con.-

nected with said attachment frame means and disposed behind said planting units, each assembly including blades shaped to engage soil in said furrows and to clear the seed depositedtherein,

. relation, a damming attachment including means serving as an attachmentframe, and a pair of rotatable damming blade assemblies movably connected with said attachment frame means, each assembly including blades shaped to engage soil in said furrows, and'means acting against said attachment frame for applying pressure to said attachment frame for holdingsaid blade assemblies in their operating position.

. WALTER H SILVER, 

